Membrane design by seele cover in Obing: Full-service lightweight construction competence, efficient loadbearing structures and innovative materials for economic and original building envelopes.

membrane structures by seele: icons of lightweight construction

No other form of construction for the building envelope changes the face of architecture as much as membrane structures and ETFE films. Lightweight structures by seele are based on light materials, efficient load-bearing structures and intelligent systems. The results are fascinating single-layer plate and shell structures and multi-layer modular forms of construction. Carrying loads, lighting, aesthetics, building physics and even controlling illumination and interior climate are the functions of mono- or multi-functional membrane and ETFE film concepts. seele is able to create delicate, low-weight building membrane skins that have a very high load-bearing capacity yet also achieve a highly aesthetic eloquence. The credibility of the designs is due to their good transparency, carefully distributed translucency or full shading, depending on needs. Light is therefore specifically used as a controllable design element.

Membranes and ETFE films in shipbuilding

Besides the design and construction of façades for buildings, seele is also involved in providing exceptional membrane structures for ships. Vibrations from the ship’s engines, acceleration forces due to the motion of the ship, high wind loads some 50m above sea level, the marine climate with its corresponding salt concentrations plus the different climate zones place tough demands on materials and combinations thereof as well as the structural design and the detailing. The use of ETFE film roofs in shipyards is a new development, which is why the technical solutions required pose great challenges. seele’s involvement in unique projects underpins its pioneering role in innovative membrane structures.

AIDAperla: seele’s contribution to one the most modern and most environmentally friendly fleets worldwide is the design and construction of four ETFE film roofs on two new ships belonging to the AIDA Cruises line. © AIDA Cruises

The total area of the ETFE film roofs on both ships is about 4,000sqm. © AIDA Cruises

Three-layer, transparent ETFE film cushions span over the pool and leisure areas of the activity decks with their “4 Elements” centrepiece. Movable roof sections enable these areas to be opened to the sky.

3D visual of film dome over “Beach Club”. Isometric view showing details of framework, GFRP (glass fibre-reinforced polymer) and ETFE film cushion connection.

3D visual showing section through steelwork supporting foil dome over “Beach Club”.

Skilful use of materials, engineering expertise, powerful ideas

Part of the seele repertoire are high-strength engineering textiles (fabrics, mesh fabrics) and film such as:

PVC-coated polyester fabric (PVC-PES)
PTFE-coated glass-fibre fabric (PTFE-glass)
Silicone-coated glass-fibre fabric (silicone-glass)
Coated or uncoated fluoropolymer fabric
ETFE-film

As a company with ISO 9001 accreditation, the quality of all processes, procedures and products is crucial for seele. Lightweight membrane designs in the form of transparent, coloured or printed ETFE film cushions or membrane shade sails in double curvature are designed and fabricated by seele with the utmost quality and precision and, depending on requirements, with or without a load-bearing structure.

It is precisely the fabrication of and connections between ETFE film that call for a wealth of experience when forming plate and shell structures in double curvature. All the relevant know-how is available at seele: high precision in the planning process, taking into account the structural and constructional influences and requirements specific to each material. Those ETFE skills are brought together by seele in an engineering department staffed by highly qualified architects, engineers, technicians and designers. The proven, acknowledged safety concept for the use of ETFE film as structural components in architecture and construction, which was developed by seele, forms the basis for all calculations.

Complex building envelopes with membrane structures created with intelligence

Architects all around the world value seele as a specialist for bespoke membrane and ETFE film designs. When it comes to high energy-related demands on the building physics or the integration of energy applications such as photovoltaic or solar thermal systems, seele’s many years of experience and great skills prove to be the key to the development and realisation of convincing engineering ideas. The potential construction options include mechanically prestressed designs in which membranes are fitted in fixed frames. However, most of seele’s membrane designs are pneumatically prestressed structures, so-called air-inflated structures. When a futuristic façade shapes the building itself, as with the Allianz Arena in Munich, then ETFE film air-filled cushions are being used, manufactured from at least two layers of ETFE films that are prestressed and stabilised by the positive or negative pressure of the enclosed volume of air. The extremely thin films resist the tension, the enclosed volume of air the compression. There is no lighter, no more efficient way of building.

Pneumatically prestressed designs: tension and compression – an ideal combination
When a futuristic façade shapes the building itself, as with the Allianz Arena in Munich, then ETFE film air-filled cushions are being used, manufactured from at least two layers of ETFE films that are prestressed and stabilised by the positive or negative pressure of the enclosed volume of air. The extremely thin films resist the tension, the enclosed volume of air the compression. There is no lighter, no more efficient way of building.

**Crystal Hall**, Baku, Azerbaijan: seele created the expressive membrane façade from PVC-PES and mesh fabrics in 2012.

**Vitam' Parc**, Neydens, France: Like a giant single-cell organism, the air-filled ETFE-foil cushions enclose the swimming pools while allowing views both in and out.

**Lyon Confluence**, France: The multi-functional membrane roof made from air-filled, transparent ETFE-foil cushions 30m above the ground forms the highlight in this part of the city. It protects the buildings below from the weather but allows daylight through for illumination.

**Canary Wharf Crossrail Station**, London: Air-filled ETFE-foil cushions form the spectacular membrane roof more than 300m long which was completed by seele/Wiehag in 2014. Some bays are left open, others are fitted with printed, matt-finish or transparent foils depending on requirements.

Movable structures and integrated media technology by seele

When the sliding ETFE roof over the pool opens on the upper deck of the AIDAprima, it’s thanks to seele. Such retractable roofs are a speciality of this company with global operations. Designs with the high corrosion resistance necessary for e.g. cruise liners include, for example, energy chains with flexible air lines, drive systems with electric geared motors, belt drives, pneumatic seals, locking mechanisms, control systems with inductive sensors and remote operation. seele also ensures that lighting and media installations are perfectly integrated into the ETFE film skin.